CVE-2026-89714

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-89714", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-11T19:38:34.751Z", "datePublished": "2026-09-11T19:46:28.476Z", "dateUpdated": "2026-10-19T08:51:27.182Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-19T08:51:27.182Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nNFS: fix delegation_hash_table leak when nfs4_server_common_setup() fails\n\nnfs4_server_common_setup() allocates server->delegation_hash_table\nfirst, but server->destroy - the only path that frees the table via\nnfs4_destroy_server() - is not assigned until the very end of the\nfunction. If any intermediate step fails (the is_ds_only_client()\ncheck, nfs4_init_session(), nfs4_get_rootfh(), or nfs_probe_server()),\nthe function returns with server->destroy still NULL, so the caller's\nnfs_free_server() skips the destroy callback and the hash table is\nleaked (4 KiB per attempt with the default delegation watermark).\n\nThis is trivially reachable from userspace: every failed NFSv4 mount\nleaks one allocation. A client that persistently retries a mount that\ncannot succeed leaks kernel memory without bound. Observed in\nproduction where a Longhorn backup poller retried mount.nfs4 against\nan NFSv3-only server roughly 10 times per second, leaking ~3.4 GiB of\nunreclaimable slab (kmalloc-rnd-13-4k) per day; the node accumulated\n12 GiB of leaked slab before the source was identified via the\nkmem:kmalloc tracepoint (call_site=nfs4_delegation_hash_alloc).\n\nReproducer:\n\n # server exports NFSv3 only (or export path absent for v4)\n while :; do mount -t nfs4 <server>:/missing /mnt; done\n # watch SUnreclaim in /proc/meminfo grow 4 KiB per iteration\n\nFree the table on the error paths between the allocation and the\nassignment of server->destroy."}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["fs/nfs/nfs4client.c"], "versions": [{"version": "f5b3108e6a14418b120a3c38ca589b8d6cf87627", "lessThan": "f3adf1643517357221422c05986d6de5df7b9913", "status": "affected", "versionType": "git"}, {"version": "f5b3108e6a14418b120a3c38ca589b8d6cf87627", "lessThan": "0fd2b9687dae36be5b84eab39b4c627bb7ab33b3", "status": "affected", "versionType": "git"}, {"version": "f5b3108e6a14418b120a3c38ca589b8d6cf87627", "lessThan": "2092f5b38f88be306140c77aeeeb43fc1adacacc", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["fs/nfs/nfs4client.c"], "versions": [{"version": "6.17", "status": "affected"}, {"version": "0", "lessThan": "6.17", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.50", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.2.4", "lessThanOrEqual": "7.2.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.3", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix"}]}], "cpeApplicability": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.17", "versionEndExcluding": "6.18.50"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.17", "versionEndExcluding": "7.2.4"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.17", "versionEndExcluding": "7.3"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/f3adf1643517357221422c05986d6de5df7b9913"}, {"url": "https://git.kernel.org/stable/c/0fd2b9687dae36be5b84eab39b4c627bb7ab33b3"}, {"url": "https://git.kernel.org/stable/c/2092f5b38f88be306140c77aeeeb43fc1adacacc"}], "title": "NFS: fix delegation_hash_table leak when nfs4_server_common_setup() fails", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["fs/nfs/nfs4client.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "f3adf1643517357221422c05986d6de5df7b9913", "status": "affected", "version": "f5b3108e6a14418b120a3c38ca589b8d6cf87627", "versionType": "git"}, {"lessThan": "0fd2b9687dae36be5b84eab39b4c627bb7ab33b3", "status": "affected", "version": "f5b3108e6a14418b120a3c38ca589b8d6cf87627", "versionType": "git"}, {"lessThan": "2092f5b38f88be306140c77aeeeb43fc1adacacc", "status": "affected", "version": "f5b3108e6a14418b120a3c38ca589b8d6cf87627", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["fs/nfs/nfs4client.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "6.17"}, {"lessThan": "6.17", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "6.18.*", "status": "unaffected", "version": "6.18.50", "versionType": "semver"}, {"lessThanOrEqual": "7.2.*", "status": "unaffected", "version": "7.2.4", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.3", "versionType": "original_commit_for_fix"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nNFS: fix delegation_hash_table leak when nfs4_server_common_setup() fails\n\nnfs4_server_common_setup() allocates server->delegation_hash_table\nfirst, but server->destroy - the only path that frees the table via\nnfs4_destroy_server() - is not assigned until the very end of the\nfunction. If any intermediate step fails (the is_ds_only_client()\ncheck, nfs4_init_session(), nfs4_get_rootfh(), or nfs_probe_server()),\nthe function returns with server->destroy still NULL, so the caller's\nnfs_free_server() skips the destroy callback and the hash table is\nleaked (4 KiB per attempt with the default delegation watermark).\n\nThis is trivially reachable from userspace: every failed NFSv4 mount\nleaks one allocation. A client that persistently retries a mount that\ncannot succeed leaks kernel memory without bound. Observed in\nproduction where a Longhorn backup poller retried mount.nfs4 against\nan NFSv3-only server roughly 10 times per second, leaking ~3.4 GiB of\nunreclaimable slab (kmalloc-rnd-13-4k) per day; the node accumulated\n12 GiB of leaked slab before the source was identified via the\nkmem:kmalloc tracepoint (call_site=nfs4_delegation_hash_alloc).\n\nReproducer:\n\n # server exports NFSv3 only (or export path absent for v4)\n while :; do mount -t nfs4 <server>:/missing /mnt; done\n # watch SUnreclaim in /proc/meminfo grow 4 KiB per iteration\n\nFree the table on the error paths between the allocation and the\nassignment of server->destroy."}], "id": "CVE-2026-89714", "lastModified": "2026-10-19T09:18:10.373", "metrics": {}, "published": "2026-09-11T20:19:58.873", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/0fd2b9687dae36be5b84eab39b4c627bb7ab33b3"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/2092f5b38f88be306140c77aeeeb43fc1adacacc"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/f3adf1643517357221422c05986d6de5df7b9913"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{"bugzilla": {"description": "kernel: Linux kernel NFS: Denial of Service due to unbounded memory leak from failed mount attempts", "id": "2532288", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2532288"}, "csaw": false, "cvss3": {"cvss3_base_score": "7.5", "cvss3_scoring_vector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "status": "draft"}, "cwe": "CWE-772", "details": ["A flaw was found in the Linux kernel's Network File System (NFS) component. When an NFSv4 mount attempt fails, the nfs4_server_common_setup() function does not properly free a memory allocation for the delegation hash table. A client that persistently retries a failed mount can exploit this to cause an unbounded kernel memory leak. This can lead to system instability and a Denial of Service (DoS) due to memory exhaustion."], "name": "CVE-2026-89714", "public_date": "2026-09-11T19:46:28Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-89714\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-89714\nhttps://git.kernel.org/stable/c/0fd2b9687dae36be5b84eab39b4c627bb7ab33b3\nhttps://git.kernel.org/stable/c/2092f5b38f88be306140c77aeeeb43fc1adacacc\nhttps://git.kernel.org/stable/c/f3adf1643517357221422c05986d6de5df7b9913"], "threat_severity": "Moderate"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[f5b3108e6a14418b120a3c38ca589b8d6cf87627,f3adf1643517357221422c05986d6de5df7b9913)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[f5b3108e6a14418b120a3c38ca589b8d6cf87627,0fd2b9687dae36be5b84eab39b4c627bb7ab33b3)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[f5b3108e6a14418b120a3c38ca589b8d6cf87627,2092f5b38f88be306140c77aeeeb43fc1adacacc)"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}, {"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "generic", "value": "6.17"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[0,6.17)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.18.50,6.19.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[7.2.4,7.3.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[7.3-rc1,*]"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}], "created": "2026-09-12T05:30:08.270679+00:00", "updated": "2026-09-15T19:30:12.150370+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"]}